For some devices, for example, emergency medical devices, it is often desirable to use these devices within a short time period after turning them on. Furthermore, users of such devices may prefer to receive an indication that the device is operating properly before starting to perform necessary medical activities. In the context of an emergency medical device such as an Automatic External Defibrillator (AED), for example, a user such as an EMS technician or bystander caregiver may require assurance that the device is starting up normally and that important subsystems are functioning properly within a few seconds of turning it on before initiating resuscitative care.